Model experiment for the interaction of solar plasma stream and geomagnetic field

A laboratory experiment is designed to study the interaction of the solar wind with the geomagnetic field. Time-exposure and time-resolved photographs are taken when plasma hits a model Earth, and direct measurements are made of the magnetic field change, plasma density and electric current distribution. The shape of the magnetic cavity formed on the upstream side of the model Earth is almost the same as that calculated for the geomagnetic cavity. The charged particles, which penetrate the magnetic cavity formed on the upstream side of the model Earth with east-west asymmetry from the neutral points on the cavity surface, appear to concentrate towards the equator on the rear side of the model, forming a westward electric current belt within the magnetosphere. When the dipole axis is not perpendicular to the plasma gun—magnetic dipole line, the invasion of plasma is more pronounced at the cusp of the cavity nearer to the gun. Charged particles appear to penetrate to a greater extent if a uniform external magnetic field is applied parallel to the magnetic dipole than if one is applied antiparallel.